Child maintenance between jobs

Hi - Hoping you can help me with something. I am currently paying child maintenance (not court mandated) for my older two children who are living with their Dad overseas. I am starting a new job, and taking the summer off to spend with my youngest (who lives with me). The two oldest will be with me for 6 weeks of the summer. I finish my old job on 15 July and start my new one on 7 September, so there will be quite a gap between pay cheques. I get that their Dad will still have bills to pay, but I'm just wondering whether I could skip a month, say August, on the grounds that a) the children will be with me so his costs will be reduced b) I will have no money coming in. What do you think? Am I despicable for even thinking of it? Just wondering how to make my last pay cheque stretch for the summer for the four of us!

Communication is a bit strained as he thinks I should be sending more than I am. (I used the UK child maintenance calculator, the one where he lives does not take account of whether you have another child in the household of the person paying.)